Hidden within a Netherlands crater is a stone bed that lets those who lie in it see the sky as a curved surface.

A dream-like maze full of strange art, surreal spaces, and fantasy landscapes to get lost in.

This museum inside Amsterdam's largest cemetery explores how people deal with death.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

Giant eggs, walls of bread, and nightmare surreality mark the largest collection of works by Salvador Dalí.

The old observatory in Copenhagen has a spiral corridor used as a racetrack.

Vortex-shaped aquarium hosts Europe's largest school of piranhas and other ocean creatures.

A 14th-century fortified keep showcases the masterpieces of an ingenious 20th-century clockmaker.

Rare wooden escalators lead deep down into an otherwise staggeringly monotonous tiled tunnel.

The patron of this extravagant Art Nouveau confection insisted that nothing less than a boat should project from its facade.

A collection of weird and wonderful art fills a former houseplant nursery.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

Catacombs turned marketplace.

The most loyal of little dogs, or a Victorian era publicity stunt?

A sweet symbol marks the place where torturous executions were once carried out.

Protecting the dead from opportunistic body snatchers.

A book bound in the skin of an infamous criminal, along with countless other specimens.

A 18th century graveyard and its astonishing cortege of macabre iconography.

17th century streets hidden under Edinburgh were once a breeding ground for the black death.

The art museum is decorated with creatively remodeled pre-Nazi swastikas.

Beneath Denmark's Højbro bridge, a bronze merman and his seven sons forever mourn for the mother and wife who left them for land.

Early habitat dioramas and home of the elusive gaff, the skvader.

Sweden's "good old days" painstakingly re-created in a model village.

It houses the remains of a 17th-century version of the Titanic.